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Login: | Explaining level changesDivision 1: Weston String Strokers v Thornbury A (Wed 19 Oct 2022)Match played between Dan Tripp (home) and Ian Johnson (away).Match won by Dan Tripp. Result: 15-7,15-9,15-10. Starting level for Dan Tripp: 1,738, level confidence: 52%. Starting level for Ian Johnson: 1,694, level confidence: 72%. Set manually. Dan Tripp to win as he is currently playing 3% better than Ian Johnson. Dan Tripp won all of the games and 63% of the points. This games result would be expected if he was better by around 55% or more. This points result would be expected if he was better by around 73% (PAR scoring). These are weighted and combined to calculate that Dan Tripp played 73% better than Ian Johnson in this match. Assuming that any level changes are shared between both players, for this result it looks like Dan Tripp actually played at a level of 2,257 and Ian Johnson at a level of 1,304. Without any damping, both players would need to be adjusted by 30% to match this result. Factoring in the relative levels of confidence which allows players with low confidence in their levels to change more quickly, the adjustment for Dan Tripp changes to +29% and Ian Johnson changes to -20%. After applying standard match damping, the adjustment for Dan Tripp becomes +12.3% and for Ian Johnson becomes -8.9%. Apply match/event weighting of 75% for 'Mixed Autumn 2022/2023' so the adjustment for Dan Tripp is +9.2% and for Ian Johnson is -6.6%. Apply limits to the amount of change for a single match which are based on player level, level confidence and time since last match so that Ian Johnson is limited to -5% level change. In general a player's level won't go up by more than 10% or drop more than 5% if they've played in the last 7 days but those limits are relaxed if their previous match was further back. Increase level confidence due to one more match played. Dan Tripp: 72%, Ian Johnson: 85%. Reduce level confidence based on how unexpected the result is. Dan Tripp: 56%, Ian Johnson: 66%. A final adjustment of +12.8% has been made to both players as part of the automatic calibration that is performed after each match. All players in this pool will have been adjusted equally in order to remain equivalent to other player pools. Final level for Dan Tripp: 2,343, level confidence: 56%. Final level for Ian Johnson: 1,664, level confidence: 66%. Notes
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